SoftBank Says It Closed Final $10B OpenAI Tranche, Bringing Stake to About 13%

SoftBank Group Corp. said on October 1, 2026 (Japan time) that it executed the third and final tranche of its follow-on investment in OpenAI Group PBC. SoftBank reports the check at USD 10.0 billion, routed through SoftBank Vision Fund 2.

That closes the USD 30.0 billion follow-on SoftBank announced on February 27, 2026. SoftBank’s own tally now puts its cumulative OpenAI investment at USD 64.6 billion and its ownership interest at approximately 13%. Those stake and dollar figures are SoftBank-reported; OpenAI has not matched them in SoftBank’s October release.

What SoftBank Announced on October 1

In its October 1, 2026 press release, SoftBank Group Corp. said it executed the “Third Tranche Investment” in OpenAI Group PBC via SoftBank Vision Fund 2 for USD 10.0 billion (JPY 1,579.6 billion at SoftBank’s stated USD 1 = JPY 157.96).

SoftBank said the tranche completes the USD 30.0 billion follow-on previously announced, bringing SoftBank-reported cumulative OpenAI investment to USD 64.6 billion and ownership to approximately 13%.

SoftBank names SoftBank Vision Fund 2 as the investing entity and OpenAI Group PBC as the target. SoftBank’s February filing described OpenAI Group PBC as a San Francisco public benefit corporation with Sam Altman as chief executive.

How the $30 Billion Follow-On Was Structured

SoftBank’s February 27, 2026 announcement laid out three equal USD 10 billion tranches, each via SoftBank Vision Fund 2, with SoftBank-stated Japan-time closings on April 1, July 1, and October 1, 2026.

That February release also stated a SoftBank-reported pre-money valuation of USD 730 billion for the follow-on, and said SoftBank would acquire preferred shares that convert automatically into common shares upon an IPO or related listing. SoftBank said it had already invested an aggregate USD 34.6 billion through Vision Fund 2 since September 2024 before this follow-on.

SoftBank’s October release points back to earlier tranche notices dated April 1 and July 1, 2026. Treat it as SoftBank’s confirmation that the planned third close happened on schedule, not as a new valuation mark.

How SoftBank Says It Paid: Senior Notes, Not the Bridge

SoftBank’s October 1 release says the third tranche was funded with proceeds from the foreign currency-denominated senior notes announced on September 24, 2026.

That September 24 SoftBank announcement described an aggregate principal amount of approximately USD 11.1 billion (SoftBank’s USD equivalent): USD 10 billion of USD notes and EUR 1 billion of EUR notes. SoftBank listed USD coupons of 8.625% (due 2030), 9.250% (due 2032), and 9.750% (due 2034), and said the notes were rated BB+ by S&P Global Ratings Japan Inc. and BB+ by Fitch Ratings Japan Limited.

SoftBank’s use-of-proceeds language tied those notes to funding the USD 10 billion third tranche and general corporate purposes, and said SoftBank expected to cancel the remaining USD 10 billion of undrawn capacity under a USD 40 billion bridge facility agreed in March 2026. The October 1 release says SoftBank canceled that remaining capacity effective September 30, 2026. Combined with an early bridge repayment SoftBank announced on September 9, SoftBank said all bridge borrowings have been repaid and no undrawn commitments remain.

Reuters coverage republished by StreetInsider summarized the same SoftBank close and the roughly USD 11.1 billion high-yield bond sale. That secondary report also said OpenAI had earlier secured USD 122 billion in commitments at an USD 852 billion valuation, with Amazon, Nvidia, and SoftBank as anchors. SoftBank’s October 1 release does not restate those round-wide figures, so treat them as Reuters-reported context, not SoftBank’s October claim.

What SoftBank and OpenAI Said When the Deal Was Signed

SoftBank’s February 27 release included management comments that still frame SoftBank’s strategy. Masayoshi Son, SoftBank’s chairman and CEO, called OpenAI a clear leader and said the additional investment would accelerate OpenAI’s research and ecosystem expansion while advancing SoftBank’s own ASI strategy. Those are SoftBank’s February words, not a new October quote. Sam Altman, OpenAI’s CEO, said in the same SoftBank release that OpenAI continues to push the frontier across infrastructure, research, and products, and called SoftBank the perfect long-term partner. SoftBank also said OpenAI shares will be marked quarterly as financial assets at fair value through profit or loss.

Confirmed vs. Unconfirmed

Why This Matters for the Broader AI Market

A completed USD 30 billion SoftBank follow-on is different from a memorandum of understanding. SoftBank is saying the cash went out, the bridge capacity is gone, and the notes were the funding path to that payment.

That sits next to other concentration stories. Nvidia’s reported willingness to back enormous OpenAI-linked infrastructure financing has already raised circular-financing questions, including our earlier look at Nvidia’s reported OpenAI debt financing talks. SoftBank’s close is separate, but it adds another mega-check to the same company.

On the public-markets side, Anthropic’s draft IPO materials have put existential-risk language and large losses in front of investors, covered in Anthropic’s IPO prospectus warnings. SoftBank says its preferred OpenAI shares convert on an IPO or listing, but these SoftBank releases do not date that listing. Policy risk is also rising: the Wall Street Journal-reported White House Super Intelligence Force story we tracked in Jay Clayton’s reported AI czar role is about oversight, not SoftBank’s balance sheet, yet a SoftBank-claimed roughly 13% OpenAI holder has reason to care. SoftBank’s October release also does not comment on OpenAI operational controversies such as the NSW parks fire-data agent access update.

What It Means for Readers in the US, Canada, Australia, and India

For U.S. and Canadian investors, SoftBank’s BB+-rated notes and SoftBank-stated coupons above 8% on multi-year USD paper show how expensive private credit gets when AI equity checks hit double-digit billions. SoftBank’s February LTV policy (below 25% normally, 35% emergency ceiling) is SoftBank’s framework, not a guarantee markets will mark OpenAI the same way.

For Australian and Indian readers, the practical signal is simpler: SoftBank finished a previously announced OpenAI package after issuing expensive senior notes and clearing a bridge facility. SoftBank has not broken out how much of OpenAI’s compute spend lands in any one country. SoftBank’s claimed ~13% ownership also does not, by itself, change ChatGPT pricing, API terms, or model release schedules.

What to Watch Next

Three SoftBank or OpenAI disclosures would move this beyond SoftBank’s October close notice: any SoftBank quarterly fair-value update on the OpenAI mark; any OpenAI confirmation of SoftBank’s ownership percentage or listing timeline for preferred-share conversion; and any SoftBank update that ties post-close leverage to the OpenAI package more clearly than the September notes and October tranche releases.

Until then, the cleanest reading is SoftBank’s own: the final USD 10 billion tranche closed on October 1, the USD 30 billion follow-on is complete, SoftBank claims about USD 64.6 billion invested and roughly 13% ownership, and SoftBank says the money came from the September senior notes while the bridge facility is fully cleared.

Frequently Asked Questions

Did SoftBank finish its $30 billion OpenAI follow-on?

SoftBank says yes. Its October 1, 2026 press release says it executed the third and final USD 10 billion tranche via SoftBank Vision Fund 2 and has now completed the USD 30 billion follow-on announced February 27, 2026.

How much of OpenAI does SoftBank say it owns?

SoftBank reports an ownership interest of approximately 13% after the third tranche, with cumulative investment of USD 64.6 billion. Those are SoftBank figures from the October 1 release.

How did SoftBank fund the final $10 billion?

SoftBank says the third tranche was funded with proceeds from foreign currency-denominated senior notes announced September 24, 2026. SoftBank described that package as about USD 11.1 billion in aggregate principal amount.

Is the OpenAI valuation SoftBank used still $730 billion?

SoftBank’s February 27, 2026 release stated a USD 730 billion pre-money valuation for the follow-on. SoftBank’s October 1 close notice does not publish a new SoftBank valuation mark. Separate Reuters reporting has cited a larger round-wide OpenAI valuation; that is not SoftBank’s October claim.

Did SoftBank sell its Nvidia stake to pay for OpenAI?

SoftBank’s October 1 and September 24 releases reviewed for this article describe senior-note funding and bridge-facility cancellation. They do not state that SoftBank sold an entire Nvidia stake to fund this tranche. Treat viral social posts making that claim as unconfirmed unless SoftBank discloses it.